Influence of the process parameters on the surface roughness, micro-hardness, and residual stresses in slide burnishing of high-strength aluminum alloys

It is well known that apart from compressive residual stresses, smooth surface and microstructuring of the surface and subsurface layers are beneficial for enhancement of fatigue strength and load-carrying capacity of structural and machine components. This complex of properties can be achieved using surface severe plastic deformation. For symmetric rotational components made of high-strength aluminum alloys, slide burnishing is appropriate because of its simplicity and easy realization. The effect of the process parameters on the surface roughness, micro-hardness, and residual stresses obtained in slide burnishing of D16T aircraft aluminum alloy has been analyzed. The optimal values of the basic governing factors, which ensure minimum roughness (up to 0.05 μ m ), have been established on the basis of a one-factor-at-the-time method, followed by a planned experiment and additional experiments. With the established combination of optimal values, the effect of number of passes and lubricant-cooler on the roughness, micro-hardness, and residual stresses in the surface being treated has been studied for two working schemes. To establish residual stress–depth profiles depending on the tool radius and burnishing force, FEM analysis of the slide burnishing process has been conducted. Thus, an evaluation of the effectiveness of slide burnishing as “mixed burnishing” has been made.